A tracheoscopic technique for obtaining uncontaminated lower airway secretions for bacterial culture in the horse

Abstract

Transtracheal aspirate (TTA) aerobic microbiology culture results from 30 ponies were compared to protected catheter brush (PCB) culture results obtained from the same ponies. The PCB procedure resulted in significantly fewer (P less than 0.05) isolates than those obtained by the TTA procedure and the PCB procedure resulted in significantly more samples with no bacteria growth than the TTA procedure. To address the possibility that the volume of tracheobronchial secretion obtained by PCB was insufficient as a microbiological sample, a sterile, double-sheathed, protected aspiration catheter (PAC) was developed. Comparisons were made between TTA and PAC aerobic microbiology culture results from 18 pneumonic foals and weanlings. There were no significant differences between the PAC and TTA procedures with respect to the number of bacteria isolates. It was concluded that the PAC technique may be used as an alternative to TTA for isolation of equine pulmonary bacteria and may be the preferred procedure because of the reduced risk of complications associated with the TTA.